저주파수의 저전압용 크로멜-알루멜 다중접합 열전변환기를 개발하고자 NiCr 히터의 두께를 400 nm. 600 nm 및 800 nm로 변화시켰다. $40;Hz{sim}10;kHz$의 직류 역방향 주파수 범위로 0.5 V의 교류 실효전압을 열전변환기에 인가시켰을 때 히터의 두께가 400 nm인 열전변환기가 ${pm}0.51{sim}{pm}1.69;ppm$ 범위의 열전효과에 의한 교류-직류 전압 변환오차를 나타내었고. 열전효과 및 주파수에 의한 교류-직류 변환오차는 $40;Hz{sim}1;MHz$의 주파수 범위에서 ${pm}40{sim}115;ppm$ 범위를 나타내어, 저주파수의 저전압용으로 사용할 수 있었다.
NiCr-heaters with three different thicknesses ranging from 400 nm to 800 nm were fabricated and their characteristics were compared for the purpose of developing a chromel-alumel multijunction thermal converter for low input voltage with low frequency. The thermoelectric effect-induced AC-DC voltage transfer difference of the thermal converter with a built-in NiCr-heater of 400 nm-thickness was ${pm}0.51{sim}1.69;ppm$ in the DC reversing frequency of $40;Hz{sim}10;kHz$ with appling $0.5;V_{rms}$ and the difference was increased to ${pm}40{sim}{pm}115;ppm$ in the frequency of $40;Hz{sim}1;MHz$, when both thermoelectric effects and frequency effects were considered, showing the thermal converter would be suitable for the low input voltage application with low frequency.
